Voice analysis versus citywide arson
While arson has been around for a long time, it is only recently, following the deterioration of the inner cities, that the subject has gained enough media prominence to become one of the staple apprehensions of the average citizen.
The city of Syracuse, NY, has recently developed its own arson squad. With a $25,000 grant from the federal government, the city appointed three Syracuse Fire Department investigators and one police officer to constitute the initial squad.
“With arson, there is usually the possibility of multiple suspects,” comments Richard Morgan, fire department investigator. “There may be five, six or more people in a neighborhood you should question; many individuals may be in a position to gain financially from a fire loss. Anything you can do to narrow the range to one or two suspects is a gain in time and the chances of apprehension and conviction.”
With part of its grant funds, the arson squad purchased a voice analyzer designed to help in narrowing this range by screening suspects during interrogation for their truthfulness in responding to questions. The device consists of a cassette tape recorder, a small computer, and an ink graph chart.
The individual being interrogated does not need to be strapped to the system, so a less stressful situation is created.
The interviewee’s replies to structured questions are spoken into a microphone. The device detects the emotional stress within a voice pattern, including even minor changes in an emotional state. The voice is constantly analyzed by the unit and a numerical value of the emotional stress is displayed.
“Things that would not be apparent to an observer are picked up by the system,” explains Morgan. “It can record a sub-audible tremor in speech that is beyond the respondent’s control. There is considerable opportunity for saving time by this procedure. No physical contact is required with the person being interviewed. All that is necessary for the investigator to do is to place the microphone in front of the respondent and ask the questions.”
Before any questions relating to the suspected arson are asked, the suspect is asked routine questions. This establishes his normal voice pattern. Only then does the investigator lead into questions relating to the incident.
If the suspect’s voice pattern changes, there is a good chance he is not telling the truth.
“The results are immediately visible during the interview,” concludes Morgan. “You know when you are in the investigation and with which person you should spend more time.”